Study of block copolymer micelles as vehicles for hydrophobic drug Lamotrigine

Objective: The objective of the study was to investigate the solubilization of poorly water-soluble drug Lamotrigine in pure & mixed Pluronic polymeric micelles. Method: Two different Pluronic (Pluronic F68, Pluronic L81) were chosen and micelle formulations were prepared by using various drug: polymer ratios and model drug Lamotrigine. Formulations were characterized by critical micellization concentration (CMC) values, cloud point of copolymers, micelle size and size distribution, zeta potential, loading efficiency, drug release and stability. Result: Mixed micelles(hydrophilic and hydrophobic) also helped to overcome the limitations of monosystem of Pluronic L81 and Pluronic F68. The solubilized drug and salt decreased the cloud point of copolymers. Results show that the solubilization of Lamotrigine enhances with the rise in concentration of block copolymers, negative Gs0 and temperature, but no significant increase was observed with added salt and at a lower pH the drug show highest solubility. Conclusion: Mixed micelles showed fairly high entrapment efficiency, loading capacity and sustained release profile for Lamotrigine, a model hydrophobe than that of plain Pluronic micelles.